Process for the production of



Reissued May 18, 1937 PATENT OFFICE PROCESS FOR THE PRODUCTION OF ETHYLENE OXIDE Theodore Emile Lefort, Paris, France, assignor,

by mesne assignments, to Carbide and Carbon Chemicals Corporation,

poration' of New York No Drawing.

New York, N. Y., a cor- Origlnal No. 1,998,878, dated April 23, 1935, Serial No. 600,578, March 22, 1932. Application for reissue September 25, 1936,

Serial No. 102,613. In

9 Claims.

This invention provides a specific and novel process for making ethylene oxide. It essentially consists in causing ethylene to combine directly with molecular oxygen at temperatures of about 150 to about 400 C. in the presence of a surface catalyst which favors the oxidation of ethylene to ethylene oxide under these conditlons. The process can be carried out at atmospheric pressure, and it may also be conducted at pressures above or below atmospheric pressure.

This process is characterized by an entirely unique reaction in which the direct addition of a single oxygen atom to the ethylene molecule occurs without the formation of significant amounts of other oxygenated compounds such as aldehydes. This novel reaction may be expressed and it is accompanied by complete oxidation of some of the ethylene to give carbon dioxide and water according to the equation:

Ethylene from any desired source may be used, including that obtained from coke oven gas, hydrogenation of acetylene, or dehydration of ethyl alcohol. The oxygen can be the oxygen of the air, and can conveniently be mixed with the ethylene prior to the reaction.

The oxidation of ethylene takes place with a giving 05 of heat, and it is, of course, desirable to maintain the temperature of the zone of reaction within the range specified. This can be facilitated by suitable dilution of the reaction gases, such as that accomplished by the use of air as the source of oxygen, and some water or carbon dioxide in addition to that formed can be admitted to the mixture in the reaction zone If desired. Hydrogen may be similarly added.

The process can be conveniently conducted by passing a mixture containing air and ethylene through a tube, for example, of silica or of a material capable of withstanding high pressures, within which is placed such a surface catalyst as one composed of silver in finely divided form, and which may be disposed within the tube on a supporting material, or in other known ways. The temperature of the reaction zone is maintained between about 150 and about 400 (3., iorexample, at about 200 C., and the issuing products from the tube contain ethylene oxide, carbon dioxide and water without objectionable aldehydes.

France March 27, 1931 The ethylene oxide can be recovered in any suitable way, preferably in liquid form by condensation or solution.

The surface catalyst is preferably silver as stated, but other metals such as bismuth and antimony may be used. Likewise oxides of these metals or mixtures containing these metals or their oxides may be used. Experiments have also indicated that the catalyst may be silver activated by the addition of small amounts of gold or copper or iron.

In any case, the ethylene and oxygen are thus reacted simultaneously at the temperatures set forth in the presence of a surface catalyst and of water, and the process is conducted to produce ethylene oxide as a direct product in substantial and economic amount. The ethylene oxide can be recovered by known methods, and it may be further reacted to form ethylene glycol or derivatives of ethylene glycol.

I claim:

1. A process for the production of ethylene oxide, consisting in subjecting ethylene to the simultaneous action of oxygen and water at a temperature between 150 and 400 C. in the presence of a catalyst composed of silver activated by small quantities of a metal selected from a group consisting of gold, copper and iron.

2. A process for the production of ethylene oxide, consisting in subjecting ethylene to the simultaneous action of the oxygen and water at a temperature between 150 and 400 C. in the presence of a catalyst composed of a mixture of silver, gold, copper and iron.

3. A process for the production of ethylene oxide, consisting in subjecting ethylene to the simultaneous action of oxygen and water at a temperature between 150 C. and 400 C. in the presence of a catalyst composed of a mixture of silver and gold.

4. A process for the production of ethylene oxide consisting in subjecting ethylene to the simultaneous action of oxygen and steam at a temperature between 150 and 400 C., and at a pressure below atmospheric pressure, in the presence of a catalyst composed of a metal selected from a group consisting of silver, gold, copper and iron, and in the presence of hydrogen in the proportion of 5 per cent of the total volume.

5. A process for the production of ethylene oxide consisting in subjecting ethylene to the simultaneous action of oxygen and steam at a pressure below atmospheric pressure. in the presence of a catalyst composed of a metal selected from a group consisting of silver, gold, copper and iron. and in the pre enc o ydr en n the the passage of said mixture through said reaction proportion 01' 5 per cent oi the total volume. and zone in the presence of said catalyst and the 01' CO1. controlled elevated temperature oi said mixture 6. A process for the production 01' ethylene oxand said catalyst to effect said oxidation of said 5 ide consisting in subjecting ethylene to the simulethylene directly to form substantial amounts of taneous action oi oxygen. steam and hydrogen at ethylene oxide; and thereafter recovering ethyla temperature between 150 and 400 C. in the cue oxide-containing product in liquid i'orm. presence 01' a catalyst composed of silver activated 9. The process of making ethylene oxide by with small quantities of gold. the direct chemical combination oi oxygen with 'l. A process for the production of ethylene oxethylene in the proportions of one atom of oxygen 1 ide consisting in subjecting ethylene to the sito one molecule of ethylene, which comprises multaneous action of oxygen, steam and hydroiorming a mixture containing ethylene and mogen at a temperature between 150 and 400 C. in lecuiar oxygen and a heat-absorbing diluent and hire 8. The process oi. making ethylene oxide by the maintain said mixture in said some at a temperadirect chemical combination of oxygen with ethture between about 150' and about 400 (3.; sub. ylene in the proportions 01' one atom of oxygen to jecting said mixture at said elevated controlled one molecule of ethylene, which comprises formtemperature to intimate contact with an active 2! ing a mixture containing ethylene and molecular surface catalyst material mposed essentially of oxygen and conducting said mixture through a silver which favors the direct oxidation 01' said confined reaction zone which is maintained at ethylene in said mixture by said molecular oxyan elevated temperature controlling said temgen to form oxidation products containin ethyl- 5 perature to maintain said mixture in said zone ene oxide in the presence of water and which at a temperature between about 150 and about does t favor t exi t in said product of 400' 6.; subjecting said mixture in said zone at substantial amounts of aldehydes; correlatingthe said elevated controlled temperature to intimate passage f said mixtur throu h said reaction contact with an active surface catalyst of a zone in the presence of said catalyst and the conmater al ha t e atalytic characteristics 01 trolled elevated temperature of said mixture and 30 ethylene in said mixture by said molecular oxyene directly to form substantial amounts of ethylgen to form oxidation products containing ethyiene oxide; and thereafter separating ethylene ene oxide in the presence of water and which oxide from the products of oxidation.

does not favor the existence in said products 35 or substantial amounts or aldehydes; correlating THEODORE Elms: LEF'ORT.

DISCLAIMER RP. 20,370.- Theodore Emile Lqfort, Paris, France. PROCESS FOR THE PRODUCTION OF ETHYLENE ()XIDE. Patent dated Nfay 18, 1937. Disclaimer filed May 14, 1942, by the ussignce, Carbide and Carbon Chemicals Corporation. Hereby disclaims claims 8 and 9 of said patent.

[Ofiicial Gazeltp June 16, 1942.] 

